Apparatus for preparing and conveying pulverized fuel



H. HARDINGE.

Oct. 31, 1933.

. APPARATUS FOR PREPARING AND CONVEYING PULVERIZED FUEL 2 Sheets-Sheet 1 Filed Feb. 11, 1930 FIGJ.

35 alum/" 5 H. HARDINGE Oct. 31, 1933.

APPARATUS FOR PREPARING AND CONVEYING PULVER IZED FUEL Filed Feb. 11, 1930 2 Sheets-Sheet 2 FIG. 3.

IIIIL Patented Oct. 31, 1933 PATENT OFFICE APPARATUS FOR PREPARING AND CON- VEYING PULVERIZED FUEL Harlowe Hardinge, York, Pa.,

assignor to Hardinge Company, Incorporated, York, Pa., a corporation of New York Application February 11, 1930. Serial No. 427,487

3 Claims.

This invention relates to apparatus for preparing and conveying pulverized fuel which is particularly applicable for feeding fuel to a furnace, but which may be used for general convey- 5 ing purposes. The apparatus which permits of the practice of the method comprises a unitary assembly including a pulverizer, a separator and an exhauster or blower connected together by conduits so as to permit of a circuitous path of travel of air currents, and a conveying conduit for conducting some of the air propelled by the exhauster and pulverized fuel to a furnace or other receiver. This apparatus embodies a defiector for controlling the quantity of air passing from the exhauster and through the pulverizer and separator whereby the'grinding and separating characteristics of the pulverizer may be controlled. The apparatus further embodies a damper to be used in conjunction with the deflec- 20 tor and for controlling the proportion of fuel to air as well as the quantity of air and fuel to be conveyed to a furnace or other receiver.

Among the objects of my invention is the pro-' duction of an apparatus which will enable an operator to maintain constant fineness of fuel for a considerable range of capacities required of a pulverizer.

Another object is to enable an operator to maintain any desired ratio of fuel to the air utilized for carrying the fuel to the furnace.

Another object 'is to reduce the operating wear and upkeep expense of moving parts in pulverized fuel pulverizing systems.

Other objects will be pointed out in the description and claims.

In the accompanying drawingst-y Figure 1 is a diagrammatic view, partly in elevation and partly in section, showing apparatus with which the general principles of my invention may be practiced;

Figure 2 is a view similar to Figure 1 showing a modified form of apparatus including astorage bin for pulverized fuel; and

Figure 3 is a diagrammatic viewpartly in elevation and partly in section of another modified form of the invention and in which an inlet is provided between the exhauster and the pulverizer to provide make-up air.

Referring'to the drawings and first to Figure 1, the apparatus includes a pulverizer, 10, the one illustrated being of the well known conical type of grinding and pulverizing mill more fully disclosed in United States Patent 1,506,120, but other kinds of pulverizers may be used if desired.

In the conical type of pulverizer, the coal or other fuel is supplied thereto by a chute 11, and balls or pebbles (not shown) within the pulverizer reduce the fuel to an impalpable powder as the pulverizer is rotated.

An exhauster 12 creates a current of air which is delivered to the pulverizer 10 through a conduit 13, and this current of air picks up and carries with it the finely powdered fuel in the pulverizer.

The discharge end 14 of the pulverizer 10 is connected with a dust collector 15, by means of a conduit 16 which delivers the fuel-laden air to the dust collector 15.

Within the dust collector 15 the pulverized fuel is extracted from the current of air and falls to the lower portion, while the separated air passes from the dust collector 15 through a conduit 17 connected therewith at its upper end. Conduit 1'7 is directly connected with the intake side of the exhauster 12.

It is evident that so long as the exhauster 12 is in operation a currentof air will follow the cycle just described, with the result that the fuel pulverized in the pulverizer 10 will be carried to the collector 15 and deposited therein. This arrange- 39 ment of the various units of the apparatus is such that substantially all the pulverized fuel is removed from the air before the air is returned to the'exhauster 12. The particles of fuel are separated from the currents of air by means of 35 the collector 15, and therefore, when the air reaches the exhauster 12 it is relatively clean. Hence, the wear on the moving parts of the exhauster 12 is greatly reduced as may be well understood.

Leading from the pressure side of the exhauster 12, is a conveying conduit 18 which serves to convey the fuel to the burner 19 of a furnace.

It is apparent that a single exhauster serves to cause the gathering of the pulverized fuel in the collector 15 as well as serves as the motive means for causing the carrying medium to carry the pulverized fuel to the burner 19.

In order to control the quantity of air passing through the pulverizer 10 and the dust collector l 15 there is provided a deflector 20, which is adjustably mounted on a pivot 21, at the junction of the conduits 13 and 18.

The deflector 20 is intended to be positioned for different operating positions so as to control the distribution of air through the pulverizer 10, and the dust collector 15. It is, by the proper positioning of the deflector 20, that an operator is enabled to maintain a uniform fineness of pulverized fuel under different capacity requirements position the passage of the air from the exhauster 12 to the pulverizer 10 is restricted and by raising or lowering the position of the deflector the velocity of the air in the pulverizer 10 is controlled.

In regulating the position of the deflector 20, to obtain a suitable product from the pulverizer 10, too much air may be directed into conduit 18. In order to control the amount of air by-passed or travelling through conduit 18, damper 22 may be regulated and the quantity of air passing through is controllable regardless of any adjustment made to deflector 20.

At the lower portion of the dust collector 15 there is a pipe 23 which communicates with the conduit 18 so that fuel may be discharged into conduit 18.

Damper 22 is disposed within conduit 18 so as to be capable of restricting the cross-sectional area of conduit 18 within the vicinity of the connection of pipe 23 with the conduit 18.

Damper 22 is intended to be adjusted so as to control the quantity of air passing through conduit 18 A restriction of the cross-sectional area of the conduit 18 at this point serves to reduce the pressure in pipe 23 so as to facilitate the discharge of the powdered fuel from the dust collector 15.

By the use of the deflector 20 and the damper 22 an operator is enabled to control the flneness of the pulverized fuel as well as to maintain the proportion of fuel to air at a substantially flxed value. J

As far as controlling the fineness of the pulverized fuel and the proportion of fuel to air is concerned it is not necessary that the damper 22 be so positioned as to aid in extracting fuel from the collector 15, for other means to be hereinafter more fully described, or a positive feeder could be used.

Air port 24 on the suction side of the system is adjustable and the amount of air required to replace the air which is passed out of the system through conduit 18, is taken in at this point.

For the ordinary installation no other air inlet port is necessary, since all of the air discharged with the fuel may be replaced in the system by proper adjustment of the size of the opening of the port 24.

As shown, the connection of the conveying conduit 18 with the pressure side of the exhauster 12 is at the periphery of the exhauster. That is, the upper portion of conduit 13 is disposed nearer to the center of the impeller of the exhauster with the result that any dust which is carried over from the collector 15 by the air currents will be caused to follow through with the air diverted into conduit 18 by the deflector 20.

In the form of the invention illustrated in Figure 2, the system comprises a pulverizer 110 having a fuel feed chute 111at its inlet end. An exhauster 112 has its pressure side connected to the pulverizer 110 by a conduit 113. The discharge end 114 of the pulverizer 110 is connected to a dust collector 115 by a conduit- 116. The dust collector 115 is also connected with the intake side ofthe exhauster 112 by a conduit 117. Leading from the pressure side of the exhauster 112 is a conveying conduit 118 which serves to convey the fuel to the burner 119 of afurnace. The connection of the conveying conduit 118 with the pressure side of the exhauster 112 is at the periphery of the exhauster for the purpose heretofore explained in of the apparatus. With the deflector in a raised the description of Figure 1. A deflector 120 is adjustably mounted at the junction of the conduits 113 and 118, said deflector being mounted on a pivot 121. A damper 122 is mounted in the conduit 118 for a. purpose similar to the damper 22 heretofore referred to.

The modification illustrated in Figure 2 functions and is controlled in the same manner as the apparatus of Figure 1.

In the form of the invention shown in Figure 2 the dust collector 115 is arranged so as to discharge into a material storage bin 125 separate therefrom or constructed as a part thereof as shown.

The discharge of the pulverized fuel from the storage bin 125 into the conveying conduit 118 is under the control of a regulating gate 126 which may be operated by a belt drive including pulley 127.

The particular positive feeder utilized is of in particular concern to the operation of the system so long as the feeding of fuel from the bin 125 may be controlled. The storage space aiforded by the bin enables a temporary high demand of fuel to be met without making it necessary to have an independent fuel reserve.

Figure 3 illustrates another system embodying the invention. This system is similar to the systems of Figures 1 and 2, except that another method of controlling the make-up air is provided.

During the operation of this system air is circulated through pulverizer 40, conduit 41, separator 42, conduit 43, exhauster 44, and conduit 45. From exhauster 44 some of the air is driven through conduit 46. In this latter conduit pulverized fuel is deposited from a separator 42 in any well-known manner. A conduit 47, which is connected to conduit 45, is positioned beyond conduit 46, so that air will be drawn into the pulverizer 40 to replace the air withdrawn from the system through conduit 46.- A damper 48, which is adjustable, controls the amount of air drawn in through conduit 4'7. This method of introducing air into the system is advantageous for using hot air to dry damp coal which is being conveyed so that packing may be prevented and the capacity of the pulverizer may be increased. Damper 49 is adjustable to suit the conditions of operation desired.

What I claim is:

1. In a device of the class described, the combination with a furnace having a burner adapted to be supplied with pulverized fuel, of a pulverizer, a collector, an exhauster, a conduit connect- 130 ing the pressure side of the exhauster with the pulverizer, conduitsrespectively connecting the collector with the pulverizer and with the intake side of the exhauster whereby air currents created by the exhauster are conducted successively through the pulverizer and collector, a by-pass conduit connecting the burner. with the conduit connecting the exhauster and the pulverizer, said connection being adjacent the periphery of the exhauster whereby material carried beyond the collector by the air will enter said by-pass conduit, means for regulating the quantity of air entering said by-pass conduit, and means for introducing pulverized material into said by-pass conduit.

2. In a device of the class described, the combination with a burner, of a pulverizer, a collector, and exhauster, a conduit connecting the pressure side of the exhauster with the pulverizer, conduits respectively connecting the collector with the pulverizer and with the intake side of the exhauster whereby air currents created by the exhauster are conducted through the'pulverizer and collector successively, a by-pass conduit leading from the conduit connecting the exhauster and the pulverizer and connected to the burner, means for introducing pulverized material into said by-pass conduit from said collector, and means for regulating the quantity of air entering said by-pass conduit.

3. In a device of the class described, the combination with a burner, of a pulverizer, a collector, an exhauster, a conduit connecting the pressure side of the exhauster with the pulverizer, conduits respectively connecting the collector with the pulverizer' and with the intake side of the exhauster whereby air currents created by the exhauster are conducted through the pulverizer and collector respectively, a by-pass conduit leadin from the conduit connecting the exhauster and the pulverizer and connected to the burner, the connection of said by-pass conduit with said first named conduit being adjacent the periphery of the exhauster, whereby material carried beyond the collector by the air will enter said by-pass conduit, means for regulating the quantity of air entering said by-pass conduit, and means for introducing pulverized material into said bypass conduit.

HARLOWE HARDINGE. 

